What is the Role of Stress in the

Development of Bulimia?

Heather Dewar





During the past few decades, Western culture has witnessed an enormous explosion in the number of eating disorders reported among young women. One such type of eating disorder is Butimia Nervosa. According to the DSM-IV criteria it is characterized by recurrent episodes of binge eating, in which the person experiences a feeling of "loss of control",and recurrent compensatory behavior in order to prevent weight gain. Both of these behaviors occur, on average, at least twice a week for three months. In addition, self-evaluation is unduly influenced by body shape and weight. Finally, there are two subcategories of bulimia. There is the purging type in which the person regularly engages in self-induced vomiting or the misuse of diuretics or laxatives. The other type is the nonpurging group in which the person engages in other inappropriate compensatory behaviors rather than self-induced vomiting, laxatives, or diuretics. (American Psychiatric Association, 1993)

Several studies have focused on stress as one important variable in the onset or occurrence of eating disorders such as bulimia. In addition, they explore the different situations or events which bulin-fics consider to be stressful and the various ways in which bulimics cope with these stressors. In this paper I plan to evaluate the effectiveness of the following related studies and attempt to answer the question, What is the role of stress in the development of DuUnfia?




Outline:

Bulimics' evaluation of Stressors

Coping Methods

Studies of the Relation of Stress and Bulimia

Effectiveness of Current Research

Conclusion




Do Bulimics Appraise Stress Differently?

It is possible that bulimics may appraise potential stressors differently from other individuals. For example, in comparison to nonbulimics, people with bulimia may appraise the situation as being more stressful, less predictable, less controllable, or less desirable. in addition, some studies indicate that bulimics experience more frequent binge eating episodes during situations which are considered to be more stressful. For example, Wolf and Crowther (1983) studied indicators of binge eating episodes among undergraduate women and found that perceptions of experiencing more stress in the past year were positively related to increased severity of binge eating. However, since stress only accounted for 6.3% of the binges it is difficult to conclude that bulimics appraisals of the stressors were different. (Cattanach, 1988)

Bulimics' Coping Mechanisms for Stress

Some theories suggest that butimics may experience coping deficits. Coping is generally defined as the cognitive and behavioral efforts to manage environmental and internal demands and conflicts affecting a person which exceed that person's resources. Coping responses are supposed to modify the effects of potential stressors. It may be that when. stressors act in combination with dieting, women who lack coping skills may be most vulnerable to developing bufimia (Lacey, 1986). Another study found that environmental stressors were indirectly related with bulimia, such that coping acted as the mediating variable. However, the study did not discriminate between the factors which precipitated and the factors which maintained the disorder. Therefore, further research must be done to determine whether coping is influencing bufimic episodes, whether bulimia is influencing coping responses, or if this process is reciprocal. (Cattanach, 1988)

A study conducted by Lopez-Ibor (I 991) supports this finding and suggests it is related to levels of serotonin

This study cites anorexia nervosa and bulimia nervosa as two well defined clinical entities among the group of eating disorders. The psychopathological differentiation of the two syndromes has a great importance for diagnosis and therapy. Based on case histories the authors state that "the presence of affective symptomology--depressive, but not exclusively--in the eating behavior disorders in general and particularly in bulirnia nervosa, is nowadays interpreted as unspecific emotional lability as a response to stressing situations." The study indicates that bulimics may be deficient in the ability to metabolize serotonin. This deficiency is manifested in the form of binges with food containing high contents of carbohydrates. In addition, high levels of serotonin seem to be associated with feelings of safety, fullness, etc. (Lopez-lbor, 1991)


Related Studies of Stress and Bulimia:

The first study which I plan to discuss was conducted by Rosen, Compas, and Tacy. The study examined the relationship among stress, psychological disorders, and eating disorders in adolescents.

Method.-

The subjects were girls chosen fi-om three independent boarding schools located in the northeast region of the United States. The study was explained in dormitory meetings and 162 of the 248 students present at the meeting returned a signed consent form and a completed questionnaire. In addition, 143 of these individuals also returned the Time 2 questionnaire. To analyze possible effects of attribution, the scores from Time I were compared to those who participated at both times and those who only participated at Time 1. The mean age of the participants was 15.9 years of age and the sample was geographically diverse originating from 33 different states.

The subects completed the questionnaires under supervision in their dormitories in January (Time 1) and May (Time 2). Four months between testing was selected so that data collections would coincide with the school semester schedule,

Subjects completed the 26-item version of the Eating Attitudes Test (EAT) which taps into the symptoms associated with eating disorders. For example, binge eating, guilt over eating, preoccupation with eating and weight, purging, etc. In addition., the participants completed the middle adolescent version of the Adolescent Perceived Events Scale which asks the individual to indicate which of 205 major and daily life events have occurred during the last 3 months. Each event which has occurred is then rated on a scale of desirability ranging from very undesirable to very desirable and a scale for impact of the event, ranging from no impact to extremely high impact. The weighted negative events score was calculated as the sum of the products of the desirability ratings and the impact ratings for the undesirable events.

Results:

The mean EAT score at Time I corresponds to the 67th percentile for female adolescent norms. Using the cutoff score for the clinical range, 24.6% fell above this level at Time 1. Therefore, the distributions for this sample on the EAT were similar to or higher than the normative data. The adolescents' Time I stress on the APES was not si@ficantly related to the EAT at Time 1, r = .1 3, p =- .08. Conversely the correlation between stress at Time 2 and eating disorder symptoms at Time 2 was significant ,r=.33,p<.001. This indicates that more stressful events were associated with more severe eating disorder symptoms at that time. In addition, at Time 2 the relation between stress and eating disorder symptoms was bidirectional. Stress predicted increased eating disorder symptoms, and eating disorder symptoms predicted increased stress. When the relation was examined over a period of 4 months, stress was more a consequence of eating disorder symptoms than vice versa. (Compras, 153-162) Although this study indicates that stress and disordered eating are related, it was not mentioned whether the eating disorder was displayed in the form of food restriction or binge eating.

Another stu eating dy linking disorders with stress was conducted by Cooper and Steere. It focused on the effects of anxiety on eating behavior. The Study compared the amounts eaten by restrained and unrestrained eaters following an anxiety-induction procedure.

Method.

The experiment consisted of several sessions and participants were paid for their participation. During the sessions, participants were encouraged to think about stressful, anxiety-producing events in their lives. Afterwards, the participants were offered to help themselves to a buffet. In addition, the participants' perceived level of hunger was assessed at the time.

Results:

Results showed that unrestrained subjects did not alter their eating in response to either anxiety or hunger. When relaxed, restrained subjects ate more when hungry than when not hungry. This finding is in agreement with previous studies. (Herman, 1987) However, in the restrained subjects, anxiety appeared to counteract the disinhibiting effect of hunger. When perceived hunger was relatively weak, anxiety did not affect the consumption of restrained subjects. However, when perceived hunger was strong, dietary restrainers ate less when anxious than when relaxed. (Cooper, 1992)

A related study by Blundell (I990) confirms the relationship between stressors and the resulting changes in eating patterns. In addition it addresses the influence of internal processes with genetic, physiological, and chemical foundation.

This study concerns the increasing occurrence of obesity over the past 50 years. It suggests that if low energy output by these persons cannot be held totally accountable for this problem, then their energy input must play a significant role. " Previously it was thought that emotional disturbances led to overeating and becoming overweight. Today it is believed that appetite is controlled by the interaction of internal (genetic, physiological, and chemical) and external (environmental and psychosocial processes." (Blundell, 1990) It further states that appetite (hyperphagia or hunger) can be induced by changes in the brain neurotransmitters and nueromodulators, altered metabolism, environmental stressors, etc.



Contrary to the previous studies which explored the relationship between stress and eating disorders as a whole, this study focuses primarily on binge eating, one characteristic of bulimia nervosa

Agras and Telch (1996) conducted this study to determine whether emotional states influence binge eating in the Obese.

Objective:

The purpose of this study was to test the hypothesis that negative affective states trigger

disinhibited eating in the form of binge eating for subjects with binge eating disorder (BED).

Method.-

Sixty females (30 with BED and 30 non-eating disordered) who responded to advertisements for a study of eating, participated in the study. Subjects who met the DSM-IV criteria for BED were considered for inclusion as were overweight NED women. The NED women were eligible if they demonstrated no evidence of binge eating, subjective sense of a loss of control over eating, purging, and /or any behaviors that would meet the criteria for an eating disorder not otherwise specified.

The procedure consisted of the BED subjects and weight-matched non-eating disordered subjects attending a laboratory experiment during which they were randomly assigned to a neutral or negative mood induction procedure. Afterwards, the participants were served a multi-item buffet.

Results:

There were no differences between the BED and NED subjects on the demographic data collected. The BED subjects averaged 43.8 years and the NED subjects averaged 44.7. The average body mass index was 34.6 for BED women and 32.2 for NED.

The results of an analysis of variance revealed significant main effects for Mood and for Time and significant interaction effects at the P>.OOI level. The results indicated that post-mood induction, participants in the negative mood condition reported a significantly greater negative mood affect than subjects in the neural mood condition.

There were no significant differences between the groups in the amount of calories consumed at breakfast and lunch by the subjects in either mood condition. The average buffet kilocalories consumed by BED subjects in the negative mood condition was 1,053 kcal and 1,241 kcal for BED subjects in the neutral condition. The NED participants consumed approximately 593 kcal and 628 kcal at the buffet in the negative and neutral conditions. A significant main effect was found which indicated that BED subjects consumed significantly more calories than NED subjects on both of the caloric measures. Furthermore, a secondary hypothesis was proposed which predicted that BED subjects who labeled the buffet eating episode as a binge would demonstrate a more negative mood compared to BED subjects who labeled the episode as overeating. This hypothesis was supported by a difference between the binge group and the overeating group on the anxiety subscale which approached significance at t = 1. 95, p<. 07. (Agras, 1996)

In addition to the studies mentioned, several other-studies have been conducted concerning stress, bulimia, and binge eating behaviors.

For example, a case study performed by Chesler (1995) describes the interaction between an anxiety disorder and an eating disorder. It showed how the interplay between stress, fear of fatness, and panic disorder with agoraphobia changed a patient's eating disorder symptoms from those of bulima nervosa to food restricting. (Chesler, 1995)

The other study was conducted with tenth grade students to assess the prevalence of purging behavior, alcohol and drug use, and reported physical and psychological distress. The results indicated that female purgers were more likely to report using alcohol to reduce stress than nonpurging female peers. Also, when perceived situational control was low, female purgers reported a higher level of psychological distress in comparison to female nonpurgers. This information provides additional support for the hypothesis that bulimics appraise stressors differently and it again indicates a link between stress and eating disorders. (Killen, 1987)

The Effectiveness of Current Research:

Current research indicates that stress definitely plays a role in bulimiaa. However, most of the findings are vague as to whether the bulimia causes additional stress or whether stress instigates the onset of bulimia. In addition, it is very difficult for studies to measure an individual's experience of stress or anxiety since these are subjective feelings. Studies have used tests such as the Adolescent Perceived Events Scale to try and measure an individual's level of stress during a time period, However, these scales may tend to give inaccurate results since different individuals may experience and cope with stress differently. Therefore, additional research in this area must focus on accurate measures of evaluating stress levels and the causal relationship between stress and eating disorders, whether stress leads to eating disorders or vise versa.

Bibliography:

Agras, S. W. & Telch, C. F. (I 996). Do Emotional States Influence Binge Eating in the Obese? International Joumal ofeating Disorders, 20, 2 71-2 79.

American Psychiatric Association. (I 993). DSM-IV &aft criteria (3/l/93). Washington, DC: Author.

Blundell, J.E. (1990). Appetite disturbance and the problems of overweight. Drugs, 39, 1-19.

Cattanach, L.M. & Rodin, J. (1988). Psychosocial Components of the Stress Process in Bulimia. International Jourml of Fating Disorders, 7, 7 5 - 8 8.

Chesler, B.E. (1995). The Impact of Stress, Fear of Fatness, and Panic Disorder with Agoraphobia on Eating Disorder Symptomatology: A Case Study. International Journal of Eating Disorders, 18,195-198.

Compas, B.A., Rosen, J.C., & Tacy, B. (1993). The Relation Among Stress, Psychological Symptoms, and Eating Disorder Symptoms: A Prospective Analysis. International Journal of Eating Disorders, 14,153-162.

Cooper, P. J. & Steere, J. (I 993). The Effects of Eating of Dietary Restraint, Anxiety, and Hunger. Intemational Journal of Eating Disorders, 13, 211-219.

Lopez-lbor, A. J. (1991). The nosological entity buhmia nervosa. Actas Luso-Espanolas de Neurologia, 19, 304-325.

Killen, J.D., Maron, D.J., Robinson, T.N., Saylor, K.E., Taylor, C.B., & Telch, M.J. (1987). Evidence for an Alcohol-Stress Link among- Normal Weight Adolescent's Reporting Purging Behavior. International Journal of Eating Disorders, 6, 349-3 56.

 

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